In the field of high-performance processing units or “supercomputers” it is known to cool the electronic cards, and in particular the electronic components mounted on them, such as integrated circuits, microprocessors and others, in order to prevent the limit values of functioning temperature from being exceeded, above which irreversible damage can be caused. Moreover, by restricting the functioning temperature range of the electronic cards by cooling them, it is possible to increase the working life of their components, at the same time reducing possible maintenance interventions.
Air cooling, that is, using a stream of forced air which is conveyed above the electronic components that produce most heat, and which is subsequently extracted from inside the container or rack of the electronic cards by means of one or more fans, does not allow an efficient removal of the heat produced, especially when there is a high density of electronic integration of the components on the cards.
Moreover, the presence of continuously moving mechanical components, such as the fans, entails the need for periodic diagnostic controls and/or maintenance in order to verify their correct functioning or to remove possible residues of impurities, such as powders or other, which can compromise the proper functioning. Such systems are also noisy and, if there are a large number of fans, they can make the work environment uncomfortable.
One cooling technique typically used for high-performance processing units is the type using liquid. This technique provides that the heat of the air heated by the electronic components of the cards is given up, inside the container, to a heat-carrying fluid which is made to circulate in a pipe, which develops, at least partly, inside the container itself. The pipe is designed, in general, to pass near the main electronic components, or near the possible auxiliary dissipaters directly mounted on the electronic components, and near the main hot points of heat production, also known as “hot spots”, of the electronic cards; it then exits from the container, or rack, in order to give up the heat thus taken in. The pipe can carry on directly toward a heat exchange device, disposed for example outside the premises where the processing unit is disposed, or it can be thermally coupled to an auxiliary pipe, hydraulically separated from it, which is in turn connected to the heat exchange device.
One drawback of this cooling technique with liquid is that, in the case of high integration of the electronic components and of high density of the hot spots, the spaces for the movement of the hot air inside the container or rack can be reduced quite considerably, and may even obstruct the desired movement of hot air toward the points provided for heat exchange on the pipe, rendering the extraction of heat inefficient and increasing the electric consumption of the processing units.
In order to at least partially improve the cooling performance and to resolve the aforesaid problems, the pipe can be designed so as to directly contact the main electronic components and the hot spots of the electronic cards.
However, one drawback of this solution is the constraints and the mechanical interferences due to the conformation and development of the pipe inside the container or rack, in which the electronic cards are housed. This, in its turn, makes it very difficult to remove the electronic cards from the container or rack, in practice increasing the times and the maintenance costs.
Moreover, cooling plates are known, for example from the patent application US2008/0296256 and from the patent JP2166755, which can be associated with the electronic cards and provided with a corresponding internal hydraulic circuit in which a heat-carrying fluid is made to flow. The cooling plates have a transverse thickness, which together with the thickness of the electronic cards themselves, makes it difficult to insert them inside the containing racks of the processing units. Moreover, the extraction of the heat is not very efficient, given that the heat-carrying fluid is hotter toward the exit from the hydraulic circuit, thus determining an inefficient cooling of some electronic components or of the relative hot spots, or requiring an over-sizing of the hydraulic circuits themselves.
Another known solution is described in U.S. Pat. No. 5,177,666, which provides to use a support element for each electronic card with a printed circuit (PCB), which acts both as mechanical support for the card and also feeds the system. This solution, because it requires a separate support element, is not very efficient, it is bulky, it cannot have any shape whatsoever, it is not adaptable to any PCB configuration, it requires a precise assemblage sequence, there are maintenance problems and still other drawbacks.
One purpose of the present invention is to obtain a cooling device with liquid for electronic cards, in particular for high-performance processing units, which allows to reduce the times and costs of maintenance and facilitates the extraction and/or insertion of the electronic cards from a relative container or rack.
A further purpose of the present invention is to obtain a cooling device with liquid for electronic cards, in particular for high-performance processing units, which allows an efficient heat removal even in the case of electronic cards with a high integration density.
A further purpose of the present invention is to obtain a cooling device with liquid for electronic cards, in particular for high-performance processing units, which allows to reduce electric consumption and to increase the working life of the processing units.
Another purpose of the present invention is to obtain a cooling device with liquid for electronic cards, in particular for high-performance processing units, which allows to minimize the bulk and overall weight of the electronic card and of the device itself, and therefore of the entire processing unit.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.